The prior art in European patent No. 80400952.0 describes a process for printing text on a support sheet consisting in associating to each character, whatever its typography or enrichment, a sequence of numerically coded characters. These sequences of coded characters have no significance for the reader. In contrast, they can be re-transcribed into printing characters by a complementary machine comprising a camera capable of recognizing the coded information, associated with a computer printer of a known type, controlled by a computer which operates the decoding of the signals delivered by the camera.
The above process presents two advantages. The first is to allow inscription on any support, in particular a paper support, in a form which is condensed and easy to exploit using a computer for translation into legible characters. The second interest is to code the characters and provide security for the written information and for its transmission by cable or radio.
In contrast, the above process presents limitations since it is not compatible with the retranscription of graphical information, for example a signature or an image.
The prior art in U.S. Pat. No. 5,602,382 describes a particular bar code format, comprising an error correction zone of the REED-SOLOMON type. It is a "proprietary" format which is not adaptable. The DCI code of the identification zone simply allows designation of the postal coding system used.
The prior art processes can be described as involving the inscription on a support, for example a label, of an assembly of usually black or white pixels, having a generally rectangular, round or square shape. Printing defects can lead to partial covering of adjacent pixels, or to deformation of printed pixels, which lead to erroneous decoding of information.
It is also known to effect a coding using a bar code which is the subject of an international standardization. These bar codes are adapted for widely used applications, which require a consensus on the format of the code.
The objective of the present invention is to improve the reliability in the reading of information printed on a support, and conferring a wide flexibility in the coding configuration, while allowing reading and use of the code with a standard and universal equipment.
To this end, the invention relates in its broadest sense to a process for coding a product which consists in affixing on the surface of a product, or optionally an animal, a marking constituted by a plurality of elementary signs belonging to at least two different types, said marking being broken down into a plurality of coding zones each corresponding to a coded information of a different nature, characterized in that the marking comprises at least one zone of configuration Cp whose content is variable and specific for each range of products, the content of said configuration zone determining at least one characteristic of at least one of the other variable coding zones specific to a product of a given range.
According to a first variant, the marking comprises at least one configuration zone which determines the format of the other coding zones.
According to a second variant which is not exclusive from the first variant, the marking comprises at least one configuration zone which determines the attributes of the other coding zones.
Preferably, the configuration zone is an initiation zone located at the start of the marking.
According to a preferred embodiment, the marking comprises a security zone whose content is determined by the result of an encoding function applied to a descriptor of the marked product. This security zone makes it possible to verify the conformity of the marked product and the absence of substitution. This variant is particularly adapted to a security marking.
According to a preferred variant, the marking is effected in the form of a matrix of N columns and M elements notably binary.
According to a particular embodiment, the marking is effected in the form of modifications of a zone of an image whose dimensions are very much larger than the marking zone.
Advantageously, the marking is effected in the form of a plurality of zones z.sub.i each constituted by juxtaposition of at least one coding band B(i).sub.j, each of these coding bands being constituted by N juxtaposed pixels P(i, j).sub.k.
The invention also relates to equipment for coding a product comprising means for marking the surface of a product by affixing a marking constituted by a plurality of elementary signs belonging to at least two different types, said marking being broken down into a plurality of coding zones each corresponding to a coded information of a different nature, characterized in that said equipment comprises a computer for affixing at least one configuration zone which determines at least one characteristic of at least one of the other coding zones.